Improving Image Resolution in Deuterium Metabolic Imaging with bSSFP for Clinical Translation at 3T

Motivation: Improve SNR and spatial resolution in deuterium metabolic imaging (DMI) on 3T in humans. Goal(s): Implement and validate a bSSFP DMI sequence; investigate whether up-take alone can be a measure for DMI. Approach: The DMI bSSFP sequence excites the whole volume with a block RF pulse, followed by 3D phase encoding, acquisition and phase rewinder. Three spatial dimensions are density-weighted phase-encoded, while spectral encoding is insufficient for separating different metabolites but used for artefact reduction. Results: Voxel size in human brain was improved from (2.4cm)3 for regular, spectrally-resolved MRSI to (1.5cm)3 for bSSFP MRSI in 10minutes scan time with minor loss in SNR. Impact: DMI provides valuable clinical information, such as tumour-treatment response, and might complement or even partially substitute PET. The significant gain in spatial resolution demonstrated here could be the missing link to establish DMI clinically on 3T.